A data center is a collection of one or more computers providing one or more functions. A data center, such as a so-called “server farm” can include tens, hundreds, or thousands of computers interconnected to provide functions, such as searching, storage, web-based hosting, email servers, transaction processing (e.g., credit checks, credit card transactions, etc.), web-based ad placement, and the like. For example, a company, such as Google, may have a data center at a facility, which includes thousands of interconnected computers to provide the processing behind Google's search engine.
Typically, the computers are organized into some form of architecture or topology. Since there can be thousands of computers in a large data center, the typical topology implements cheaper, lower capacity switches (so-called “edge” switches) to connect directly to the computers. The traffic from those edge switches is typically aggregated and switched using fewer but more expensive, higher capacity switches. The topology thus allows any given computer in the data center to access (e.g., send and receive packets) another computer in the data center.